I have african violets and one other house plant. I have small flying knats coming from plants. How do I get rid of insects?

Lorna, sounds like fungus gnats or shore flies. Their maggots can live in soils that are kept moist. They feed on decaying organic matter. Generally they are just a nusiance but high populations of young can feed on roots. Try letting the soil surface dry between watering or transplant into new soil.